1. Field of the Invention
The invention relates generally to computer equipment and more particularly to devices and methods for entering full alphanumeric character sets with a keypad having only a small number of buttons.
2. Description of the Prior Art
When both the space and cost of a full alphanumeric keyboard can be accommodated in a computer system or instrument, each key can be dedicated to a particular character. Standard personal computer keyboards for English therefore feature individual keys for numbers 0-9, letters A-Z and a-z, punctuation and arithmetic operators.
Keyboards that come with a fixed set of characters each printed on a key button typically require a large number of keys to accommodate a rich character set for any particular language and alphabet. Such keyboards are, by definition, inflexible. Other languages and alphabets require hardware changes, and/or data entry method changes to accommodate large character sets.